The present invention relates to the field of poured concrete structures. In particular, the invention relates to a non-metallic web reinforcing strip for poured concrete structures. The invention is especially useful when the concrete structure in which it is incorporated is likely to be subjected to a corrosive environment.
It is conventional to reinforce poured concrete structures with prefabricated rigid metal bars (commonly known as xe2x80x9crebarxe2x80x9d), semi-rigid steel meshes, and the like. However, metal reinforcing structures present problems when a corrosive environment confronts the concrete structure. For example, bridge decks in coastal areas are often exposed to corrosive seawater and mists. Snow and ice removal materials can also be corrosive. Because they are metallic, corrosion can affect the reinforcing structures, causing them to weaken and expand with oxide buildup. The resulting expansion of the metal reinforcing means can cause the surrounding concrete to crack and fail under heavy loads.
Galvanizing or coating the metal reinforcing structures with epoxy coatings reduces the risk of corrosion but greatly increases the cost of the reinforcing structures. Fixed length rigid glass reinforced resin (GFR) bars are available as alternatives to metal reinforcing structures, but such bars must be completely fabricated in the desired shape at the factory and cannot be bent or reshaped in the field later.
Therefore, a primary objective of the present invention is the provision of a nonmetallic webbed reinforcing strip for poured concrete structures that is an improvement over existing reinforcing structures used in such concrete structures.
A further objective of this invention is the provision of a reinforcing strip that is a nonmetallic and the therefore resistant to corrosion.
A further objective of this invention is the provision of a nonmetallic webbed reinforcing strip that is strong, compact, economical to manufacture, and easy to install.
These and other objectives will become apparent from the drawings, as well as from the description and claims which follow.
The webbed reinforcing strip of this invention includes a first elongated tension strand, a second elongated tension strand spaced apart from and substantially parallel to the first tension strand, and at least two pairs of strands interconnecting the first and second tension strands in an open weave pattern. The interconnecting strands cross each other between the tension strands to form the webbed central portion of the strip. The interconnecting strands bend to join the tension strands at non-perpendicular angles at a plurality of connection nodes. All strands are formed of a glass fiber reinforced material bonded together with a plastic resin. Thus, thermal transfer and the potential for damage due to corrosion are minimized.
Such strips can be used as reinforcements in a variety of poured concrete structures, including slabs and columns. The strips can be chaired and tied into the forms before the concrete is poured. The reinforcing strip of this invention is nonmetallic so that it can withstand corrosive environments better than steel reinforcing bars or mesh.